The Vertical Seismic Profiling (VSP) logging operation was successfully conducted for the first time in country under high-pressure, high-temperature (HPHT) conditions in well QT-03 of the Qezel Tappeh field. The operation was carried out from a depth of 4,850 meters up to near surface at a temperature of 338°F and a pressure of 15,000 psi.

The Geoscience and Drilling Operations teams of Pezhvak Energy Engineering Services Company (PECO) executed this operation in collaboration with the wireline logging service team from Garfa Vista Kish Company (GVK-Renhe ). The operation utilized Hostile VSP tools in a Zero-Offset configuration and two vibroseises owned by Kish Petroleum Engineering Company (KPE). The project was completed within a single day under the supervision of geophysics engineers from the Exploration Management Company (NIOC-EXP).

The main objective of this operation was to obtain a high-resolution seismic profile around the well, which would enhance the interpretation of extensive surface seismic data previously acquired in the Qezel Tappeh field.

Key Outputs from VSP Seismic Data Interpretation:

1. Determination of the depth of formation tops and geological interlayers.

2. Development of a velocity model for seismic wave propagation in geological formations for correlation with surface seismic data.

3. Calculation of acoustic impedance based on rock density and wave velocity characteristics.

4. Processing and comparison of P-wave (compressional) and S-wave (shear) data to determine Poisson’s ratio and wave attenuation coefficient.

5. Identification of anisotropy properties, porosity, fluid saturation, microfractures, and structural boundaries.

6. Monitoring reservoir changes over time to evaluate the impact of production and enhanced oil recovery (EOR) activities.

7. Reducing exploration risks and costs by providing more reliable data for well placement and reservoir evaluation.

The execution of this operation shows the technical expertise and commitment of the engineering and operational teams at PECO to gather maximum information needed for studies and development of oil and gas fields, which they have undertaken under EPD contracts.